| Title: Can soil respiration measured at mean temperature represents actual soil respiration |
| author: “Jinshi” |
| date: “March 26, 2019” |
| output: |
| html_document: |
| df_print: paged |
| bibliography: bibliography.ris |
1. The spatial destribution of global Rs sites
- We have much more measured Rs from the middle latitude region
- It is difficult to measure soil respiration all year around in the cold region
- Developed contries most located at Middle latitude region, thus recieved more funds to support the Rs measurements
Global spatial destribution of soil repiration sites
- Rs measurements from cold region is more importent, but how to increase the measurements?
- Making equipment works normal in cold condition
- Increase funds input
- Measured once per day to get daily mean
- Measure once per year to get a annual Rs mean? Bahn’s approach [Bahn et al. (2004) Biogeosciences]
- Rs measured at annuam mean temperature linearly related with annual Rs rate
- Rs at mean temperature: soil respiration measured at annual mean temperature / monthly mean temperature / daily mean temperature
- Rs_annual ~ Rs_mat (Rs_bahn)
- Rs_annual = 455.8 * Rs_mat^1.0054 (R^2 = 0.94, p<0.001)
2. The object of this analysis are
- Whether Rs measured at annuam mean soil temperature can represent annual Rs rate?
- Annuam mean air temperature (e.g., average of 12 monthes’ air temperature of 2000) / Mean annual air temperature (1964-2014)
- If not, when and what is the mechanism?
- Update the model?
3. Mthods
Data
- SRDB_V4 – Rs_Annual
- Annual mean soil temperature (reported in the papers or can be calculated with simple assumption)
- Relationship between Rs and soil temperature (SRDB_V4)
- Air temperature (University of Daleware global precipitation and air temperature data, 1964-2014, half degree spatial resolusion)
- 823 records from 253 studies
Statistics
- According the the relationship between Rs and Ts, we can estimate Rs_mat base on the annual mean soil temperature / T_Annual / MAT
- Using Bahn (2010, Biogeoscience model: Rs_annual = 455.8 * Rs_mat^1.0054) to predict Rs_annual based on Rs_mat
- Comparing Rs_annual and Rs_annual_bahn to evaluate the performance of Bahn model across the global
Update Bahn’s model
- If Bahn (2010) model does not predict Rs_annual in all conditions
- Update Bahn (2010) model (e.g., including drought parameter, other parameters?)
- Regression tree modeling?
3.2 test the relationship between Rs_annual and Rs_mat
## Tue Apr 2 15:56:24 2019 -------------------
## Tue Apr 2 15:56:24 2019 Bahn relationship for these data:
##
## Call:
## lm(formula = Rs_TAIR ~ Rs_annual, data = sdata)
##
## Residuals:
## Min 1Q Median 3Q Max
## -1006.45 -84.72 14.90 93.38 964.58
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 0.64266 13.67584 0.047 0.963
## Rs_annual 0.85184 0.01466 58.126 <2e-16 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 185.1 on 821 degrees of freedom
## Multiple R-squared: 0.8045, Adjusted R-squared: 0.8043
## F-statistic: 3379 on 1 and 821 DF, p-value: < 2.2e-16
## [1] "test intercept=0 and slope=1"
## [1] "p_intercept = 0.9625, p_slope = 0"3.3 Ts sources (MGRsD, MGRsD_TAIR, From paper, Rs_Ts_relationship)
## Saving 7 x 5 in image
3.4 Annual Rs or Ts coverage effect
## Saving 7 x 5 in image
## Saving 7 x 5 in image
3.4.1 Test whether outliers affect the regression (require update)
- Conclusion: need update the code and results
## Saving 7 x 5 in image
## Saving 7 x 5 in image
3.4.2 Effect of maximum allowed divergence between global climate data set and site-specific air temperature
- Does TAIR_dev and TAIR_LT<_dev affect the relationship – YES!!!!!
- TAIR_LTM_dev = with( srdb, abs( MAT_Del - MAT ) )
- Does TAIR_LTM_dev () pull the slope off 1? – YES!!!!!
- TAIR_dev <- with( srdb, abs( TAnnual_Del - Study_temp ) )
- Figure E. Effect of maximum allowed divergence between global climate data set and site-specific air temperature, when given. As we throw out data points with high divergence, R2 goes up (top panel) and RSE goes down (bottom, g C m-2 yr-1).
## Saving 7 x 5 in image
## Saving 7 x 5 in image
3.4.3 Effect of maximum allowed divergence between annual precipitation from paper and Del
4. Results
4.1 Using Ts, TAnnual or MAT
4.1.1 Using soil temperature
## Saving 7 x 5 in image
4.1.2 Using T_Annual
## Saving 7 x 5 in image
4.1.3 Using MAT
## Saving 7 x 5 in image
4.2 Analysis when Rs_mat cannot represent Rs_annual
4.2.2 Does Ecosystem_type affects the relationship between Rs_annual and Rs_mat
## Ecosystem R2_mv Slope_mv p_slope_mv intercept_mv
## Rs_annual Agriculture 0.80 1.08 0.0001 -6.25
## Rs_annual1 Forest 0.74 0.87 0.0042 94.20
## Rs_annual2 Grassland 0.82 1.12 0.0000 -33.00
## Rs_annual3 Shrubland 0.81 1.08 0.0001 -3.57
## Rs_annual4 Wetland 0.80 1.08 0.0001 -4.97
## p_intercept_mv MSE_mv
## Rs_annual 0.7245 235.24
## Rs_annual1 0.0167 271.45
## Rs_annual2 0.0617 217.13
## Rs_annual3 0.8376 233.75
## Rs_annual4 0.7765 234.40## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## Ecosystem R2_kp Slope_kp p_slope_kp intercept_kp
## Rs_annual Agriculture 0.74 1.04 0.7725 38.73
## Rs_annual1 Forest 0.83 1.13 0.0000 -43.81
## Rs_annual2 Grassland 0.73 0.88 0.0459 89.44
## Rs_annual3 Shrubland 0.68 0.74 0.1066 101.92
## Rs_annual4 Wetland 0.80 0.92 0.5972 63.88
## p_intercept_kp MSE_kp
## Rs_annual 0.6262 170.87
## Rs_annual1 0.0199 217.52
## Rs_annual2 0.1264 316.26
## Rs_annual3 0.3434 174.53
## Rs_annual4 0.4887 159.16## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## Saving 7 x 5 in image
## Saving 7 x 5 in image
## Saving 7 x 5 in image
## Saving 7 x 5 in image
## Saving 7 x 5 in image
## Saving 7 x 5 in image
## Saving 7 x 5 in image
## Saving 7 x 5 in image
4.2.3 Does Meas_method affects the relationship
## Saving 7 x 5 in image
## Saving 7 x 5 in image
## Saving 7 x 5 in image
## Saving 7 x 5 in image
4.2.4 RA or RH dominated sites differ?
## Saving 7 x 5 in image
4.2.5 Biome effect
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
## geom_path: Each group consists of only one observation. Do you need to
## adjust the group aesthetic?
4.2.6 TAIR and precipitation variability affect?
## Saving 7 x 5 in image
## Saving 7 x 5 in image
4.2.7 Does drought affect?
## Saving 7 x 5 in image
## Saving 7 x 5 in image
5. Discussion & questions
6. More analysis in the future
- 1 Using SD information with boosting?
- 2 Use Rs_mat predict Rh?
- 3 Use this approach estimate global Rs
- 4 Think about application
- 5 Update bahn model with more predictors or using regression tree method?